Converter for mechanical pencils



July 10, 1956 F. LANE CONVERTER FOR MECHANICAL PENCILS Filed Sept. v2, 1955 FIG. 2

FIG. 3

FRANK L. LANE IN V EN TOR.

FIG. I

ATTORNEY CONVERTER FOR MECHANICAL PENCILS Frank L. Lane, Oklahoma City, Okla.

Application September 2, 1955, Serial No. 532,337

6 Claims. (Cl. 120-9) The present invention relates to mechanical pencils, and more particularly to a device for converting a mechanical lead pencil to a liquid graphite replaceable cartridge pencil.

Many individuals have macthing pen and pencil sets and are desirous of using a liquid graphite pencil, but are reluctant to break the appearance of their matching set by using a different colored or appearing pencil, for sentimental reasons.

It is therefore the principal object of this invention to provide a device for converting a mechanical lead pencil to a liquid graphite cartridge holding pencil.

Another object of this invention is to convert a mechanical lead pencil to a liquid graphite pencil by using the body and cap of the pencil to retain the original appearance of the same.

An additional object is to provide a device of this class which may be easily installed in a mechanical lead pencil by anyone, without the use of special tools.

A further object is to provide a device of this class which is easily assembled and dismantled for replacing used liquid graphite cartridges therein.

A still further object of this invention is to provide a device which may be comparatively cheaply manufactured, and therefore may be sold at a relatively low cost.

The present invention accomplishes these and other objects by providing an anchor sleeve to be carried by the body of the mechanical pencil. The sleeve has one conical shaped end complementally seated against one end of the body and provided with an axial passage for receiving and holding a liquid graphite cartridge writing tip end. A carrier tube is frictionally disposed within the body and projects beyond the end of the body opposite the conical tip for frictionally engaging and holding the mechanical pencil cap in axial alignment with the body. Plug means carried within the tube hold the end of the cartridge opposite the writing tip. The adjacent ends of the sleeve and tube are longitudinally adjustably connected for impinging the cartridge between the conical tip and the plug.

Other objects will be apparent from the following description when taken in conjunction with the accompanying single sheet of drawings, wherein:

Figure 1 is a longitudinal cross sectional view of a mechanical pencil body and cap with the device of the present invention installed therein; and

Figures 2 and 3 are longitudinal cross sectional views of the device, per se.

Like characters of reference designate like parts in those figures of the drawings in which they occur.

In the drawings:

The reference numeral indicates, as a whole, a mechanical lead pencil having a substantially cylindrical body 12 from which the lead holding mechanism has been removed. The body has one abrupt end 14 perpendicular to its longitudinal axis and has its opposite end portion formed into a frusto-conoidal tip 16. The

aired States Patent O cap 18 is cylindrical in general configuration and diametrically substantially equal with relation to the body 12 and has one open end adapted to abut the end 14 of the body. The above description is generally conventional with mechanical lead pencils and forms no part of the present invention and is presented here to show an operable conventional mechanical pencil housing within which the device is installed.

An anchor sleeve 30 of a selected length having one end portion of its wall roll threaded, as at 32, and having its opposite end formed into a truncated conical tip 34 terminating in an annular shoulder 36 perpendicular to its longitudinal axis, is axially disposed within the body 12. Diametrically the sleeve 30 is such that it may be inserted into the body 12 from the conoidal end 16 until the shoulder 36 seats against the frusto-conoidal tip. The periphery of the shoulder 36 is complemental with the adjacent surface of the conoidal tip portion 16. The conical tip 34 is provided with a reduced axial passage or bore 38 which frictionally receives and holds the writing tip portion 40 of a replaceable liquid graphite cartridge 42., for the purposes more fully explained hereinbelow.

A carrier tube 44 of a selected length and having a diameter which is frictionally received by the bore of the body 12 and the cap 18 is inserted into and projects beyond the body from the end 14. One end portion of the tube 44 has its wall diametrically reduced and roll threaded, as at 46, for complementally engaging the exterior or threaded portion 32 of the anchor sleeve. The end 48 of the tube is perpendicular to its longitudinal axis. The wall of the tube 44 is circumferentially upset at a point adjacent to, and parallel with, but spaced from the end 48 to form an annular retaining ring 50.

A cylindrical plug 52 of plastic, or other slightly resilient material, having a diameter slightly larger than the bore of the retaining ring 50, is forced into the tube 44 from the end 48 beyond the ring 50. The inwardly disposed end of the plug 52 is provided with a central bore forming a socket for closely receiving the end of the cylindrical cartridge 42 opposite the writing tip end 40. The cartridge 42 is inserted into the sleeve 30 from the end 14 of the body. The tube 44, with the plug 52 in place, is then inserted into the body 12 engaging the threads 32 and 46. The free end of the cartridge 42 is nested by the socket in the plug 52 and thereafter the tube 44 is manually rotated on the threads 32, seating the plug 52 against the ring 50 and tightly impinging the cartridge 42 between the plug and the axial passage 38.

A conventional eraser 54 may then be inserted into the open end 48 of the tube, if desired. The cap 18 is then longitudinally placed over the outwardly projecting end of the tube 44. When it is desired to replace the cartridge 42, the cap 18 is removed and the tube 44 unscrewed from the anchor sleeve 30 and a new cartridge inserted, as disclosed hereinabove.

Obviously the invention is susceptible to some change or alteration without defeating its practicability, and I therefore do not wish to be confined to the preferred embodiment shown in the drawings and described herein, further than I am limited by the scope of the appended claims.

I claim:

1. In an adapter for holding a liquid graphite cartridge in a mechanical pencil, the combination with a hollow cylindrical body and a removable cap of substantially equal area cross sectionally, said body having a frustoconoidal tip portion, of: an anchor sleeve having an exteriorly threaded end portion and having a reduced conical tip end portion provided with an axial passage for receiving the writing tip of said cartridge, said conical tip end terminating in an annular shoulder perpendicular with the bore of said body and said cap for holding the two in complemental axial alignment, said tube having a reduced end portion enveloping the adjacent end of said sleeve, the wall of said tube internally up-set adjacent the end opposite said reduced end forming an annular retaining ring therein; means longitudinally adjustably connecting the adjacent end of said sleeve and said tube; and a resilient plug closely received by the bore of said tube between said reduced end and said retaining ring and having one end seated against said ring, said plug having a bored socket in its end opposite said seated end for holding the end of said cartridge opposite the writing tip, whereby said carrier tube may be longitudinally adjusted relative to said anchor sleeve to tightly impinge said cartridge between the conical tip and said seated plug.

References Cited in the file of this patent UNITED STATES PATENTS 

1. IN AN ADAPTER FOR HOLDING A LIQUID GRAPHITE CARTRIDGE IN A MECHANICAL PENCIL, THE COMBINATION WITH A HOLLOW CYLINDRICAL BODY AND A REMOVABLE CAP OF SUBSTANTIALLY EQUAL AREA CROSS SECTIONALLY, SAID BODY HAVING A FRUSTOCONOIDAL TIP PORTION, OF: AN ANCHOR SLEEVE HAVING AN EXTERIORLY THREADED END PORTION AND HAVING A REDUCED CONICAL TIP END PORTION PROVIDED WITH AN AXIAL PASSAGE FOR RECEIVING THE WRITING TIP OF SAID CARTRIDGE, SAID CONICAL TIP END TERMINATING IN AN ANNULAR SHOULDER PERPENDICULAR TO THE WALL OF SAID SLEEVE, SAID ANCHOR SLEEVE CONCENTRICALLY DISPOSED WITHIN SAID BODY, WITH SAID ANNULAR SHOULDER SEATED AGAINST THE CONOIDAL TIP OF SAID BODY; A CARRIER TUBE HAVING A PERIPHERY CLOSELY RECEIVED BY THE BORE OF SAID BODY AND SAID CAP, SAID TUBE HAVING A REDUCED INTERNALLY THREADED END PORTION FOR COMPLEMENTALLY ENGAGING THE THREADED END OF SAID ANCHOR SLEEVE, THE WALL OF SAID TUBE 